Operator&#39;s cord-circuit with reverting busy-test.



C. S. WINSTON.

OPERATORS com) CIRCUIT WITH REVERTING BUSY TEST.

APPLICATION FILED SEPT-11,1913- Patented June 6; 1916.

UNITED STATES PATENT oEEicE.

CHAR-LES S. WINSTON, OF CHICAGO, ILLINOIS, ASSIGNOR TO KELLOGG SWITCHBOARD 82: SUPPLY COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

OPERATORS CORD-CIRCUIT WITH REVERTING BUSY-TEST.

Specification of Letters Patent.

Patented June 6, 1916.

Application filed September 11, 1913. Serial No. 789,290.

To all whom it may concern Be it known that I, Ci-rAnLEs S. WINSTON, a citizen of the United States of America, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Operators Cord-Circuits with Reverting Busy-Test, of which the following is a specification.

My invention relates to telephone systems, and more particularly to common battery multiple systems, and has for its object the provision of improved busy test arrangements.

More particularly my invention contemplates the provision of what I may call a reverting busy test by which I mean the provision of a circuit in which the operator receives a distinctive indication whenever a test is being made on a party line, one of whose telephones is initiating the call.

My invention is particularly devised to provide this reverting busy test in connection with a subscribers operators cord circuit arranged for automatic and secret listening arrangements. The cord circuit herein which is adapted to provide this distinctive busy test for party lines has means for automatically cutting in the operators head set with the cord circuit whene er a connection is made by the answering plug, and has provisions for automatically disconnecting this operators circuit when the connection is finally completed by the insertion of the calling plug.

I will describe one form of carrying out my invention more in detail by referring to the accompanying drawing, in which a telephone system arranged in accordance with my invention is diagrammatically illustrated. I here set forth in this drawing a subscrihers station A which is united by means of line conductors 1 and 2 with a cen tral station E terminating at this central station in the answering ack 3 and multiple jack 4. Any ordinary subscribers circuit is available for use in connection with my invention, the one shown herein including the receiver 5, transmitter 6, call signal 7, imaedance coil 8 and condenser 9; The line lamp 10 at the central station is controlled by the line relay 11, and later on when the plug is inserted, by the cut-off relay 12. It is thought this part of the circuit will be clear without further explanation. I also show a subscribers line consisting of the line wires 13 and 1 1, which is provided with subscribers party line stations 0, D, E and F. These party line subscribers stations each have talking equipment similar to that shown for the sub-station A, except that as herein shown when used in connection with the particular circuit herein shown, they are provided with harmonic signal receiving devices 15, 16, 17 and 18, respectively, which respond respectively to the currents of different frequency as supplied by generators 19, 20, 2 1 and 22 at the central station. This party line circuit for purposes of illustration is here shown as terminating in an answering jack 23 and multiple jack 24. The customary line lamp 25, line relay 26, and cut-oft" relay 27 are provided for this party line circuit similarly as provided for the single subscribers circuit before mentloned. The cord circuit for making connections has the answering plug 28 and calling plug 29. Each jack has a thimble denoted respectively by the reference numerals 30, 31, 32 and 33. The thimbles 32 and 33 are connected together as shown and are included serially with the cut-01f relay 12 and ground. Similarly the thimbles and 31 are connected together and included with their corresponding cut-ofi relay 27 to the ground. These thimbles are used for test purposes as will be presently pointed out, and as is clear from the illustration, also form part of the circuit through their respective cut-oft relays. The cord circuit consists of the tip strand 3st and the sleeve strand 35. Condensers 36 and 37 are in eluded for purposes well understood. The operators talking circuit 38 is connected in parallel with the strands of the cord circuit by the cut-in relay 39 which through the agency of contact levers 40 and 41 controls the circuit to the conductors 42 and 43 of this operators circuit. Whenever an answering plug 28 is inserted in the jack there is completed a circuit from the ground 44, cut-off relay 27, thimble 30, Contact 15, conductor 4L6, conductor 47, relay 39, through battery to ground. This energizes the cutoff relay 27 and also energizes the relay 39 whereupon the operators circuit '38 is conneeted in bridge with the cord circuit which circuit may be traced from the connection point 48, conductor 49, contact lever 50, conductor 51, contact lever 41, conductor 13, operators set 38, conductor 42, contact lever 40, conductor 52, contact lever 53, conductor to the connection point It will be seen that the connection points 48 and 55 are respectively on the tip and sleeve strands of the cord circuit. The answering supervisory relay 56 having two windings with battery interposed has these windings connected in bridge with the cord circuit, thus to control the answering supervisory signal 57, as will be readily apparent.

The generators 19, 20, 21 and 22 are controlled respectively by the selective key springs 58, 59, 60 and G1 to establish the desired frequency from the grounded generators on the conductor 62 which conductor then is adapted for connection to the tip strand. of the cord circuit through the agency of the contact lever under the coir trol of the interrupter relay This interrupter relay 6% is controlled by the ringing key 65, by means of which whenever a sub scriber is to be called circuit is completed from the ground at 66 through battery, through relay 6%, conductor 10S, ringing key springs 67, conductor 68, conductor 69, contact spring 7 0, conductor 71, contact spring 72, to ground It will of course be understood that the operators circuit cut-out relay 73 has been energized by the insertion of the calling plug 29, thus to complete the circuit from conductor 71 to ground. At the same time a circuit is established from the ground 106 through battery, through relay 7d, conductor 60, to the contact spring 70, and from there over the same path to ground, thus also energizing the relay 7i to thereby throw the interrupter 107 into the circuit. The ringing key 05 is then released, but relay 74: remains energized through the agency of the spring 7 6 which completes the circuit hitherto completed by the ringing key. This maintains the connection between the interrupter 107 and the contact spring 77, so that an interrupted circuit is provided for the interrupter relay 6% which may be traced from the ground through the interrupter 107, spring 77, conductor 78, ringing spring 67, conductor 10S, relay 6%, through battery to ground at 66. The ringing con ductor 62 is thus alternately connected to the tip strand to periodically ring the called subscriber. Immediately upon the response of the called subscriber the calling sleeve relay 79 is energized thereby breaking the circuit through the relay 7% at the contact spring 70, thus preventing further opera tion of the relay 64 and thereby preventing further connection of ringing current to the, called line.

It may be pointed out that the condenser 80 proydded in the operators talking circuit has one of its poles charged to a certain potential from battery which can be traced from ground at 81 through battery, through the relay 79, sleeve strand 35, contact spring 82, conductor 5%, contact spring 53, conductor 52, spring 40, conductor i2 to one pole of the condenser. This of course occurs whenever an answering plug has been inserted. Now, if at this time the calling plug 20 should be touched to the thimble 33 for instance, of a subscribers line which is busy, hen this thimble 33 will have a battery potential thereon which can be traced from the ground at S2 through battery, relay 73, contact 109 to the thimble The thimble 33 is thus charged similarlv to the char ed Job: of the condenser 80. T he opposing pole of the condenser 80 is of course by induction then oppositely charged. Now if the tip 83 of the calling plug 29 is connected to a thimble 33 thus charged, then a circuit is established by which the pole of the condenser which has the induced charge is connected through con ductor 13, contact spring 41, conductor 51, contact spring 50, conductor d9, contact spring 8i, tip strand of the cord circuit, tip 83, to the thimble Thus the pole of the condenser which has hitherto had the induced charge will be raised to the same potential as the yn'eviously charged pole of the condenser, thus causing a discharge of current whereby the operators receiver 85 receives a click to indicate that the line is busy. It will, of course, be seen that when the tip 83 is connected to the thimble 33 it said thimble is charged, then the calling tip relay S0 and relay 87 are energized while this test is being made. The circuit through the relay 87 can be traced from the ground, through said relay 87, conductor 88, contact spring 89, conductor 90, contact spring 91', to the tip of the cord circuit, and from there to the charged thimble 33. And similarly the circuit through the relay 86 can be traced from the ground through said relay 86 directly to the tip strand of the cord circuit. 'lhespring 89 of course is in circuit closing position because the relay 39 remains ener gized if the answering plug 28 is in the jack :23. This operation of these two relays however, does not cause any disturbance as will be readily apparent. New should the answering plug 28 be in the ack F23 and should one of the telephone stations C, for instance, desire communication with telephone station F, on the same line, then the tip. 83 would be brought into contact with the thimble 31. Under these conditions a circuit would be established from the charged thimble 31 through the tip 83 and from. there through the relays 86 and S7 to energize the same similarly as when testing on the jack of another line. It may be pointed out that the relay S7 is common to an operators position. The operation of the relay 87 under all conditions serves to establish a circuit from ground 93 through a winding 9% of an induction coil, condenser 95, con- Cir ductor 96, contact spring 97, conductor 98, contact spring 99, contact spring 100, conductor 101, conductor 46, to the thimble contact 45 of the plug 28 which having been assumed as within the jack 23 thus is connected to the thimble 30. The thimble 30 is thus grounded through the coil 94. The coil 94 is under the influence of a primary coil 102 which through the agency of a commutator 103 and battery 10st imparts to the coil 9% distinctive interrupted currentconditions, thus to cause distinctive potential changes of the thimble 30. The thimble 30 is of course connected to the thimble 31 and thus these distinctive potential changes are communicated to the tip 83 thus to alternately charge and discharge the condenser as will be readily apparent whereby the operator receives a distinctive test when testing back on a calling party line. During the conversation the relay 79 is of course energized, this energization being eiiected when the calling party answers to thereby eliminate the calling supervisory signal 105, and this energization of this relay 7 9 will prevent the special tone from the coil 94: from being placed upon the sleeve of the answering cord when the relay 87 for instance, is energized, due to tests being made by other calling cords in the same position. As before stated, the operators circuit is connected by the cut in relay 39 directly in bridge of the cord circuit. Now the moment the plug 29 is inserted in the jack of the called for line, relay 7 3 is energized, thus through the agency of springs 50 and 53 to break this operators circuit, thus to automatically cause disconnection of said operators circuit from this particular cord.

From what has been described it is thought it will be entirely clear that I have provided a reverting busy test arrangement for a cord circuit of the automatic and secret listening type. It will, of'course, also be readily apparent that many changes and modifications may be made and other circuits used without departing from the spirit of my invention.

Having. however, thus described one form which my invention may take, what I claim as new and desire to secure by Letter Pat ent is:

1. A telephone exchange system having entering party lines, each provided with a plurality of terminating jacks, a test thimble for each jack, and a link circuit for completing the electrical connection between jacks having an operators set and means for automatically connecting and disconnecting said set with conductors of said circuit, said link circuit having meansopera lo only during the testing operation for changing during said testing operation the test conditions of a thimble connected therewith.

2. A telephone exchange system having entering party lines, "each provided with a plurality of terminating jacks, a test thimble for each jack, and a link circuit for completing the electrical connection between jacks having an operators set and means for automatically connecting and disconnecting said set with conductors of said circuit, said link circuit having means operable only during the testing operation for chang ing during said testing operation the test ble connected therewith, said means including electromagnetic apparatus common to said link circuits, and each link circuit also having means to prevent such test condition changes in its associated thimbles when said common apparatus is actuated by the testing operations of another link circuit.

4. A telephone exchange system having entering party lines, each provided with a plurality of terminating jacks, a test thimble for each jack, a plurality of link circuits for completing electrical interconnections between jacks, an operators set and means for automatically connecting and disconnecting said set with conductors of said circuits, said link circuits each having operable during the testing operation means for changing during said testing operation the test conditions of a thimble connected therewith, said means including electromagnetic apparatus common to said link circuits, and each link circuit also having means to prevent such test condition changes in its associated thimbles when said common apparatus is actuated by the testing operations ot another link circuit.

5. A telephone exchange system having entering party lines, each provided with a plurality of terminating jacks, a test th.i1n ble for each jack, a plurality of link circuits for completing electrical interconnections between jacks, an operatorsset and means for automatically connecting and disconnecting said set with conductors of said circuits, said link circuits each having operable during the testing operation means for changing during said testing operationthe test conditions of a thimble connected therewith, said means including electromagnetic apparatus common to said link circuits, and 4 to orevent such condition changes see thimhles when said common actuated by the testing operaanother link circuit.

exchange system haying env, c '1 1 ,i 1 k co P110 u uith a pin-- raid? of t thiible for each llzeele :ctionbetu'ee jac an o tors set and means for cally connecting and disc with conductors of said c h cuit liz-iying means operable during the testopcration for changing during saic testmg operation the tOSL conditions of a thinr ble connected therewith, said last aforesaid means including a source of distinctive current and a relay adapted to associate said source with said connected thimble.

tepl one exchange s tein haying .raticn tor changing during ooeration the test conditions of l 1 l cmiuccteu taerewith, said last aforesauil means including a source of tinctive current and a relay adapted to associate said source with said connected thinlble. the circuit through said rela v being controlled by said first ator said means.

8. )hone exchange system having ente a ty lines, each provided with a plurality terminating jacks, a test thimble for each ack, and a link circuit for comileting l 1 electrical connection between jacks na an operatofis set, a supervisory re ay and means for LllbCllllllilCtlllV connectl mg and disconnecting said set with conducor said circuit, said link circuit having means operable during the testing operation for changing during said testing operation the test conditions of a thimble connected therewith, said last aforesaid means including a source of distinctive current and a relay adapted to associate said source with said connected thimble, the circuit tl'irough said relay being controlled by said firs aforesaid means, and the circuit through said source being also controlled by said supervisory relay.

9. A telephone exchange system having entering party lines, each. provided with a plurality o1? terminating jacks, a test thimbio for each jack, and a link circuit for completing the electrical connection between jacks having an operators set, a supervisory relay, and means for automatically connecting and disconnecting said set with conductors of said circuit, said link circuit having means operable during the testing operation for changing during said testing operation the test conditions of a thinible connected therewith, said last aforesaid means including a source of distinctive current and a relay adapted to ass ciate said source with said connected thimble, the circuit through said relay being controlled by said first aforesaid means, and the circuit through said source being also controlled by said su pcriisory relay.

10. A telephone exchange system having entering party lines, each provided with a plurality of terminating acks, a test thimll-l0 for each ack, a plurality of link circuits or completing electrical interconnections v.etween jacks, an operators set and means for automatically connecting and disconnecting said set with conductors of said circults, said link circuits each having operable duringthe testing operation means for changing during said testing operation the test conditions of a thimble connected therewith, said means including electromagnetic apparatus conunon to said link circuits, and each link circuit also having means operable when said link circuit is connected with two jacks to prevent such test condition changes in its associated thimbles when said common apparatus is actuated by the testing operations oi another link circuit, said last aforesaid means including a superyisory relay.

ll. In a testing system the combination with a telephone line having a busy testing terminal, of an operators link circuit provided with a testing contact for testing the busy condition of the line, means for automatically connecting and disconnecting an operators set with the conductors of said link circuit. testing circuit including a conductor of the answering end of the cord adapted to be closed when a lousy line is tested, and means associated with said circuit for interrupting the current flow therein whereby when said circuit is closed a special tone is produced in the operators set.

12. In a testing system the combination with a telephone line of a plurality of substations upon said line, a plurality of test ing contacts for said line at the central office. a link circuit provided with means for automatically connecting and disconnecting an operators set with the conductors of said link circuit. a testing terminal associated with said link circuit, a busy testcircuit adapted to be closed when the link circuit terminal is connected to the test terminal of a busy line. and a tone signal circuit adapted to be. closed over a conductor of the answering end of said link circuit when said line is busy whereby the tone is transmitted to the operators set.

13. In a testing system the combination with a telephone line having a busy testing terminal, of an operators testing contact for testing the busy condition of the line, a link circuit provided with means for automatically connecting and disconnecting an op erators set with the conductors of said link circuit, said link circuit having its answer ing end connected with the line, a test circuit including a conductor of the answering end of the link circuit closed when a busy line is tested, and a suitable device for interrupting the current flow in said circuit whereby when said line is tested a special tone is produced in the operators set.

1%. A telephone system comprising party lines each provided with a plurality of terminal jacks, a link circuit provided With terminals for interconnecting the said lines, means for automatically connecting and disconnecting the operators set with the conductors of said link circuit, and means for connecting a distinctive tone through the answering terminal of said link circuit to the operators set when the said answering terminal is connected to a calling line and the calling terminal of said link circuit is brought into engagement with a jack of said calling line.

15. A telephone system having party lines each provided with a plurality of terminal jacks, a link circuit provided with terminals for completing electrical connection between jacks having an operators set and means for automatically connecting and disconnecting the said set with conductors of said link circuit, and means for connecting a distinctive tone current with the test contact of said jacks when one subscriber on a line requests connection with a second subscriber on the same line and the operator tests a jack of said calling line.

Signed by me at Chicago, county of Cook and State of Illinois, in the presence of two witnesses.

CHARLES S. WINSTON.

'Witnesses:

G. E. MUELLER, M. R. Rocnronn.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

